It is not easy to always get a good wholesale price for fresh vegetables as their quality can be compromised due to long transportation and an inconsistent storage temperature environment.
According to Kerry Hultin, Marketing Coordinator of OctoFrost, IQF frozen vegetables have the advantage of being affordable to customers and available on different markets all year round. “The wholesale price of fresh vegetables heavily depends on whether it’s in season and the current demand, which can be unstable. To make a profit at the wholesale prices, it’s important that good quality vegetables are offered at the right time. There is an abundant amount of a vegetable available when it’s in season, which makes it less profitable due to lower prices. When fresh vegetables are not in season, however, there is more demand than supply and farmers find it challenging to fulfill orders. In 2018, the Chinese export of frozen vegetables to Japan rose 7%, with stem vegetables such as broccoli and spinach accounting for the most significant increase. The demand for frozen spinach is growing in Japan; its export from China increased by 14% in 2018.”
Why choose frozen spinach over fresh
Hultin understands that consumers automatically assume fresh vegetables are healthier than their frozen counterparts. She states that isn’t always the case: “Consumers assume that fresh vegetables are more nutrient-dense than frozen vegetables. This is rarely the case. Fresh vegetables usually require long-distance transit. On average, it takes one to four weeks for fresh vegetables to reach the grocery stores. While being transported, fresh vegetables remain packed and can easily get bruised or rotten, causing a loss in both nutrients and appearance. It’s common for a delicate and highly perishable leafy green like spinach to decay and get slimy, meaning it will lose its value. Fresh spinach usually sits in the supermarkets for quite a few days until a consumer finally purchases it. These vegetables can be exposed to various conditions or inconsistent storage temperature, which in turn could cause the quality of the vegetables to decrease significantly. Research has shown that the amount of vitamins and minerals in frozen spinach may be more than the fresh ones. Frozen spinach is especially rich in Vitamin E and Vitamin B.”
Best practice – Processing spinach
Although there are multiple ways to process or freeze spinach, Hultin states IQF-freezing is the best way to do so. “An important aspect of preserving good quality spinach is to not only IQF freeze, but to also make sure one goes through the correct processing steps prior to the IQF-freezing process. After spinach is harvested, the color, texture and aroma start to change rapidly, because the enzyme activity continues. This results in a loss of the spinach’s nutritional value and by the time it reaches the consumers’ plates, you could question how much nutrition is actually left in them. Processing freshly harvested spinach on-site does reduce the amount of nutrients that is lost in the process.”
Blanching and Chilling – lock in the nutrients
“To deactivate enzymes and preserve spinach's dark green color, nutrients, crisp texture and fresh aroma, quick blanching is a crucial step. If you want to achieve consistent product quality, blanching with water provides more accurate temperature than steaming does. OctoFrost IF Blancher allows a second temperature zone to reduce the temperature in the final blanching stage for delicate products like spinach to avoid over-blanching. The rainfall shower system in the OctoFrost Blancher provides 5 to 10 times more water volume, infiltrating spinach leaves for a uniform and quick blanching.” Hultin explains.
“For achieving the best possible texture and color, spinach is chilled immediately after blanching to stop the blanching process quickly and avoid over-blanching. OctoFrost IF Chiller guarantees a quick and even chilling because of the ice-cold water that gently falls over the product through the rain shower system. The temperature in OctoFrost™ IF Chiller is always kept under the critical 6 C° to inhibit bacteria growth.”
Dewatering – Keep good product separation
In order to avoid spinach leaves stick together after dewatering and also eliminate lump formation during the freezing stage, OctoFrost has come up with a new piece of equipment that separates the dewatered spinach: “To avoid lump formation in the IQF-freezing stage, spinach must be dewatered after blanching and chilling. Dewatering wet spinach can be done in two ways. You can press the spinach under a spring-loaded cylinder or use a centrifuge. These methods can shape lumps of spinach that will need to be loosened up before freezing. This is why we have developed a new piece of equipment; a tedder that gently rakes and separates the already dewatered spinach.” Hultin explains.
IQF Freezing – the finishing touch
The difference between IQF-freezing and regular slow freezing methods is the forming of water crystals at the cellular level of product. Hultin explains quick freezing keeps the shape and nutrients of the product intact: “IQF Frozen spinach can be stored for a long time; its nutritional value is preserved due to quick freezing at a very low temperature that deactivates enzymes and stops microbes' sprouting. With slow freezing methods, bigger sizes of water crystals formed at the cellular level of products destroy its cell structure. Therefore, the product loses its shape when defrosted, which also means loss of juices and nutrients. However, IQF quick freezing forms only small water crystals inside the spinach cells without damaging the cell walls, therefore preserving the leaf's natural shape. The result of high-quality IQF freezing is a good-looking defrosted spinach leaf, full of nutrients and flavor.”
“The high quality result that the OctoFrost IQF achieves can be attributed to a couple of deatures in the line. The bedplates in OctoFrost IQF Freezer use asymmetrical movement to create gentle fluidization, thus smoothly separating IQF spinach leaves. The OctoFrost™ fans' speed is adjustable to keep off spinach from overblowing into the coil.”
“The OctoFrost's deep understanding of the complex processing of sticky, fragile, and delicate products such as IQF spinach, makes the OctoFrost IQF Processing line a unique solution for processors who have at heart the goal of offering the best quality products to today's discerning consumers.” Hultin concludes.